I have some of these symptoms as well and unfortunately it doesn't seem like there is a definite answer. I had a stomach virus and went to the doctor because I had neck pain and a low fever... wanted to make sure it wasn't meningitis or anything more serious. It was only a stomach virus. I honestly am thinking that I have chronic sinus allergies (causing headaches, face and head pressure, eye tiredness and soreness, headaches, any throat issues) and possibly TMJ disorder (causing jaw and neck pain, headaches, soreness in mouth). I am going to look into TMJ disorder next month when I visit my dentist. I notice that I do clench my teeth sometimes while sleeping or even while awake. I feel dizzy quite often and get vertigo often. One time I used a sinus nose spray and the dizziness and pressure did improve, but my throat felt very sore afterwards! This shows that I definitely had some blocked up sinuses, and then the drainage irritated my throat even more.
These are just some ideas. Do you think any of this may be a possibility for you? I haven't really been getting any other allergies at this time of year. Also, any fever? My temperature is completely normal (other than when I had the stomach virus). I also feel pretty wiped out and exhausted quite often, even with good sleep. I haven't been able to find someone to help me out with these symptoms and am just trying to look into it more on my own. I already have some other health issues to take care of first and get tired of paying many copays to visit specialists and get no help!